1 sachet (which is supposed to be a serving for 1) of oats so simple has 16g of carbs, + 9g of carbs in 180ml of semi skimmed milk = 24g of carbs for a standard serving. I don't think knocking it up to 30g would require a "massive" bowl of porridge.
But there's no need to knock it up to 30g. Or to cut out carbs. Have you done a DAFNE course or looked into carb counting? That might help with how to accurately count the carbs you're consuming, and how to bolus for them.
My fitness pal is fine. Just bear in mind that some of the data is user entered, so whoever filled it in might have not been bothered about carbs or might have made an error. So do do a sense check on what it's telling you (I had some out of the chiller pre made spinach and ricotta sauce the other day, scanned the bar code on the pot for myfitnesspal to tell me how many carbs in it, it told me it had 53g, which didn't sound right, I checked the label and actually it had 5.3g, which is quite a difference when bolusing) And do make sure it's calculating carbs on the right weight or serving size that you are actually having.